I grew up in Eastbourne (parents still there) but wasn't in to triathlon back then. There is life guard cover from the pier to somewhere else. Don't remember any changing facilities other than the private huts. If you are going to swim the sea be careful, its very tidal there and there are strong currents. I did the MCS Big Sea Swim a couple of years back, turned at one buoy and was hardly moving and I am a good swimmer.

Running - there are few parks. Princes Park near the seafront. Has a lake you can run around but its not that big and I recall the path is narrow. Best bet for a run is along the promenade. It goes all the way from the sovereign center to beechy head. Its wide and when I lived there no bikes were allowed on it. Good for an out and back run. The Eastbourne Tri starts on the sea front and goes along the prom and then up the big hill towards St Bede's school

Gildridge park is nice although not very big, not sure what running would be like. Hampden Park is quite big, only thing I can remember about that is there used to be a flasher there when I was at scholl nearby.

Cycling - Want a nice gentle Z1 pedal there is the Cuckoo Trial which goes for miles, and old train track. Hills you need to head out towards beechy head / East Dean. There is a hill called Butts Lane which we all used to cycle up when I was in to Mountain Biking. You will be turining round and coming back down if you are on a roadie though but its a fun hill. Once out past East Dean there are some good villages and quiet roads around. Keep off the main roads though. The trunk roads in and out of Eastbourne are all single carriage way and v. busy. If you don't want hills head out stones cross and on to the quiet roads that way towards Herstmonceux.

The traffic is terrible. The main roads in and out (A27/A259) are single carriage way. The A27 is especially bad lots of accidents which clog the road for ages. I used to work outside Brighton and it could take me anywhere between 40 mins and 2.5 hours. Good idea to train after work and wait out the worst of it.

Lifeguards are between pier and wish tower - wish tower hill is good for hill repeats also